Areas that are usually affected include cheeks, ears, nose and fingers and toes. Frostbite is often preceded by frostnip. The symptoms of frostbite progress with prolonged exposure to cold. Historically, frostbite has been classified by degrees according to skin and sensation changes, similar to burn classifications. However, the degrees do not correspond to the amount of long term damage. A simplification of this system of classification is superficial (first or second degree) or deep injury (third or fourth degree).

Grade 1: if there is no initial lesion on the area, no amputation or lasting effects are expected

Grade 2: if there is a lesion on the distal body part, tissue and fingernails can be destroyed

Grade 3: if there is a lesion on the intermediate or near body part, autoamputation and loss of function can occur

Grade 4: if there is a lesion very near the body (such as the carpals of the hand), the limb can be lost. Sepsis and/or other systemic problems are expected.

A number of long term sequelae can occur after frostbite. These include transient or permanent changes in sensation, paresthesia, increased sweating, cancers, and bone destruction/arthritis in the area affected.

Affected feet may become numb, by erythema (turning red) or cyanosis (turning blue) as a result of poor blood supply, and may begin emanating a decaying odor if the early stages of necrosis (tissue death) set in. As the condition worsens, feet may also begin to swell. Advanced trench foot often involves blisters and open sores, which lead to fungal infections; this is sometimes called tropical ulcer (jungle rot). If left untreated, trench foot usually results in gangrene, which may require amputation. If trench foot is treated properly, complete recovery is normal, though it is marked by severe short-term pain when feeling returns.

Trench foot is a medical condition caused by prolonged exposure of the feet to damp, unsanitary, and cold conditions. It is one of many immersion foot syndromes. The use of the word "trench" in the name of this condition is a reference to trench warfare, mainly associated with World War I, which started in 1914.

An aerosol burn is an injury to the skin caused by the pressurized gas within an aerosol spray cooling quickly, with the sudden drop in temperature sufficient to cause frostbite to the applied area. Medical studies have noted an increase of this practice, known as "frosting", in pediatric and teenage patients.

Adiabatic expansion causes the gas (with a low boiling temperature) to rapidly cool on exit from the aerosol applier. According to controlled laboratory experiments, the gas from a typical deodorant spray can reduce skin temperature by up to sixty degrees Celsius.

The form of injury is freezing of the skin, a type of frostbite. It is highly advised for those who suffer from frostbite to seek medical attention.

In rare cases aerosol-induced burns can be severe enough to necessitate skin grafting.

Depending on the duration of exposure aerosol-induced frostbite can vary in depth. Most injuries of this type only affect the epidermis, the outermost layer of skin. However, if contact with the aerosol is prolonged the skin will freeze further and deeper layers of tissue will be affected, causing a more serious burn that reaches the dermis, destroys nerves, and increases the risk of infection and scarring . When the skin thaws, pain and severe discomfort can occur in the affected area. There may be a smell of aerosol products such as deodorant around the affected area, the injury may itch or be painful, the skin may freeze and become hardened, blisters may form on the area, and the flesh can become red and swollen.

Signs and symptoms vary depending on the degree of hypothermia, and may be divided by the three stages of severity. Infants with hypothermia may feel cold when touched, with bright red skin and an unusual lack of energy.

Hypothermia is often defined as any body temperature below . With this method it is divided into degrees of severity based on the core temperature.

Another classification system, the Swiss staging system, divides hypothermia based on the presenting symptoms which is preferred when it is not possible to determine an accurate core temperature.

Other cold-related injuries that can be present either alone or in combination with hypothermia include:

- Chilblains: superficial ulcers of the skin that occur when a predisposed individual is repeatedly exposed to cold

- Frostbite: the freezing and destruction of tissue

- Frostnip: a superficial cooling of tissues without cellular destruction

- Trench foot or immersion foot: a condition caused by repetitive exposure to water at non-freezing temperatures

The normal human body temperature is often stated as . Hyperthermia and fever, are defined as a temperature of greater than .

The areas most affected are the toes, fingers, earlobes, nose.

- Blistering of affected area

- Burning and itching sensation in extremities

- Dermatitis in extremities

- Digital ulceration (severe cases only)

- Erythema (blanchable redness of the skin)

- Pain in affected area

- Skin discoloration, red to dark blue

Chilblains usually heal within 7–14 days.

Chilblains — also known as pernio, chill burns and perniosis — is a medical condition that occurs when a predisposed individual is exposed to cold and humidity, causing tissue damage. It is often confused with frostbite and trench foot. Damage to capillary beds in the skin causes redness, itching, inflammation, and sometimes blisters. Chilblains can be reduced by keeping the feet and hands warm in cold weather, and avoiding extreme temperature changes. Chilblains can be idiopathic (spontaneous and unrelated to another disease), but may also be a manifestation of another serious medical condition that must be investigated. A history of chilblains suggests a connective tissue disease (such as lupus). In infants, chilblains together with severe neurologic disease and unexplained fevers occurs in Aicardi–Goutières syndrome, a rare inherited condition.

Symptoms may include a change in skin color to red or black, numbness, pain, skin breakdown, and coolness. The feet and hands are most commonly involved.

Gangrene is a type of tissue death caused by not enough blood supply. Symptoms may include a change in skin color to red or black, numbness, swelling, pain, skin breakdown, and coolness. The feet and hands are most commonly involved. Certain types may present with a fever or sepsis.

Risk factors include diabetes, peripheral arterial disease, smoking, major trauma, alcoholism, HIV/AIDS, frostbite, and Raynaud's syndrome. It can be classified as dry gangrene, wet gangrene, gas gangrene, internal gangrene, and necrotizing fasciitis. The diagnosis of gangrene is based on symptoms and supported by tests such as medical imaging.

Treatment may involve surgery to remove the dead tissue, antibiotics to treat any infection, and efforts to address the underlying cause. Surgical efforts may include debridement, amputation, or the use of maggot therapy. Efforts to treat the underlying cause may include bypass surgery or angioplasty. In certain cases hyperbaric oxygen therapy may be useful. It is unknown how commonly the condition occurs.

A blood blister is a type of blister that forms when subdermal tissues and blood vessels are damaged without piercing the skin. It consists of a pool of lymph, blood and other body fluids trapped beneath the skin. If punctured, it suppurates a dark fluid. Sometimes the fluids are cut off from the rest of the body and dry up, leaving behind dead cell material inside the blister with a texture like putty. Some blood blisters can be extremely painful due to bruising where the blister occurred.

There are also blood blister-like aneurysms as these are known to be located in the supraclinoid internal carotid artery and have been recognized as having unique pathological and clinical features.

Blood blisters are commonly caused by accidents in which the skin is pinched by a tool, mechanism, or heavy weight without protective gear. Blood blisters can also arise from forcible human contact, including grappling.

Blood blisters also may occur with friction caused by constant rubbing of skin against a surface. Because of this, baseball pitchers, rowers, and drummers often contract blood blisters on the fingers and palms. They also form as a result of frostbite.

Blood blisters can also occur in the mouth for a variety of reasons including, but not limited to, side effects to certain medications, nutritional deficiencies, and mouth injuries.

A blister may form when the skin has been damaged by friction or rubbing, heat, cold or chemical exposure. Fluid collects between the epidermisthe upper layer of the skinand the layers below. This fluid cushions the tissue underneath, protecting it from further damage and allowing it to heal.

Intense rubbing can cause a blister, as can any friction on the skin if continued long enough. This kind of blister is most common after walking long distances or by wearing old or poorly fitting shoes. Blisters are most common on the hands and feet, as these extremities are susceptible while walking, running, or performing repetitive motions, such as joystick manipulation whilst playing certain video games, digging with a shovel, playing guitar, etc. Blisters form more easily on moist skin than on dry or soaked skin, and are more common in warm conditions. Less-aggressive rubbing over long periods of time may cause calluses to form rather than a blister. Both blisters and calluses can lead to more serious complications, such as foot ulceration and infection, particularly when sensation or circulation is impaired, as in the case of diabetes, neuropathy or peripheral artery disease (PAD).

Knee pain is pain in or around the knee.

The knee joint consists of an articulation between four bones: the femur, tibia, fibula and patella. There are four compartments to the knee. These are the medial and lateral tibiofemoral compartments, the patellofemoral compartment and the superior tibiofibular joint. The components of each of these compartments can suffer from repetitive strain, injury or disease.

Running long distance can cause pain to the knee joint, as it is high-impact exercise.

Acrocyanosis is characterized by peripheral cyanosis: persistent cyanosis of the hands or of the hands, feet, or face. The extremities often are cold and clammy and may exhibit some swelling (especially in the warmer weather). The palms and soles exhibit a wide range of sweating from moderately moist to profuse, but all peripheral pulses should have normal rate, rhythm, and quality. Exposure to cold temperatures worsens the cyanosis, while it often improves on warming. Aside from the color changes, patients normally are asymptomatic and therefore there is usually no associated pain. The most common sign, discoloration, usually is what prompts patients to seek medical care.

Acrocyanosis is persistent blue or cyanotic discoloration of the extremities, most commonly occurring in the hands, although it also occurs in the feet and distal parts of face.

The principal (primary) form of acrocyanosis is that of a benign cosmetic condition, sometimes caused by a relatively benign neurohormonal disorder. Regardless of its cause, the benign form typically does not require medical treatment. A medical emergency would ensue if the extremities experience prolonged periods of exposure to the cold, particularly in children and patients with poor general health. However, frostbite differs from acrocyanosis because pain (via thermal nociceptors) often accompanies the former condition, while the latter is very rarely associated with pain. There are also a number of other conditions that affect hands, feet, and parts of the face with associated skin color changes that need to be differentiated from acrocyanosis: Raynaud’s phenomenon, pernio, acrorygosis, erythromelalgia, blue finger syndrome. The diagnosis may be challenging in some cases, especially when these syndromes co-exist.

Acrocyanosis may be a sign of a more serious medical problem, such as connective tissue diseases and diseases associated with central cyanosis. Other causative conditions include infections, toxicities, antiphospholipid syndrome, cryoglobulinemia, neoplasms. In these cases, the observed cutaneous changes are known as "secondary acrocyanosis". They may have a less symmetric distribution and may be associated with pain and tissue loss.

Common deformities of the knee include:

- Genu varum

- Genu valgum

- Genu recurvatum (Knee hyperextension)

- Knee flexion deformity

- Bipartite patella

Acroosteolysis is resorption of the distal bony phalanges. Acroosteolysis has two patterns of resorption in adults: diffuse and bandlike.

The diffuse pattern of resorption has a widely diverse differential diagnosis which includes: pyknodysostosis, collagen vascular disease and vasculitis, Raynaud's neuropathy, trauma, epidermolysis bullosa, psoriasis, frostbite, sarcoidosis, hypertrophic osteoarthropathy, acromegaly, and advanced leprosy.

The bandlike pattern of resorption may be seen with polyvinyl chloride exposure and Hadju-Cheney syndrome.

A mnemonic commonly used for acro-osteolysis is PINCHFO.

Pyknodysostosis, Psoriasis,

Injury (thermal burn, frostbite),

Neuropathy (diabetes),

Collagen vascular disease (scleroderma, Raynaud's),

Hyperparathyroidism,

Familial (Hadju-Cheney, progeria),

Occupational (polyvinyl exposure),

Acroosteolysis may be associated with minimal skin changes or with ischemic skin lesions that may result in digital necrosis.

Reduced blood flow to the skin layers may result in mottling or uneven, patchy discoloration of the skin

Since oxygen is carried to tissues in the blood, insufficient blood supply causes tissue to become starved of oxygen. In the highly aerobic tissues of the heart and brain, irreversible damage to tissues can occur in as little as 3–4 minutes at body temperature. The kidneys are also quickly damaged by loss of blood flow (renal ischemia). Tissues with slower metabolic rates may undergo irreversible damage after 20 minutes.

Clinical manifestations of acute limb ischemia (which can be summarized as the "six P's") include pain, pallor, pulseless, paresthesia, paralysis, and poikilothermia.

Without immediate intervention, ischemia may progress quickly to tissue necrosis and gangrene within a few hours. Paralysis is a very late sign of acute arterial ischemia and signals the death of nerves supplying the extremity. Foot drop may occur as a result of nerve damage. Because nerves are extremely sensitive to hypoxia, limb paralysis or ischemic neuropathy may persist after revascularization and may be permanent.

Paresthesia is an abnormal sensation such as tingling, tickling, pricking, numbness or burning of a person's skin with no apparent physical cause. The manifestation of a paresthesia may be transient or chronic, and may have any of dozens of possible underlying causes.

The most familiar kind of paresthesia is the sensation known as "pins and needles" or of a limb "falling asleep". A less well-known and uncommon but important paresthesia is formication, the sensation of bugs crawling underneath the skin.

Paresthesias of the hands, feet, legs and arms are common, transient symptoms. The briefest, electric shock type of paresthesia can be caused by tweaking the ulnar nerve near the elbow. Similar brief shocks can be experienced when any other nerve is tweaked (a tweaked neck nerve may cause a brief shock-like paresthesia toward the scalp). In the older age group, spinal column irregularities may tweak the spinal cord briefly when the head or back is turned, flexed, or extended into brief uncommon positions (Lhermitte's sign). The most common, everyday cause is temporary restriction of nerve impulses to an area of nerves, commonly caused by leaning or resting on parts of the body such as the legs (often followed by a pins and needles tingling sensation). Other causes include conditions such as hyperventilation syndrome and panic attacks. A cold sore outside the mouth (not a canker sore inside the mouth) can be preceded by tingling because a cold sore is caused by herpes simplex virus. The Varicella zoster virus (Shingles) also notably may cause recurring pain and tingling in skin or tissue along the distribution path of that nerve (most commonly in skin, along a dermatome pattern, but sometimes feeling like headache, chest or abdominal pain, or pelvic pain).

Other common examples occur when sustained pressure has been applied over a nerve, inhibiting or stimulating its function. Removing the pressure typically results in gradual relief of these paresthesias. Most pressure-induced paraesthesia results from awkward posture, such as engaging in cross-legged sitting for prolonged periods of time.